If the photograph is clicked, it grows.

HP 5384A 10Hz-225MHz Frequency Counter SOLD OUT　SOLD	fre71

Channel A Characteristics Range: 10 Hz to 100 MHz Sensitivity: [MAIN LEVEL] off 15 mVrms sine wave 50 Hz to 100 MHz 25 mVrms sine wave 10 Hz to 50 Hz 45 mV pk-pk 5 ns minimum pulse width Dynamic Range: 45 mV to 4 V pk-pk × attenuator setting. Coupling: AC Impedance: X1: 1 Mohm NOMINAL | | <25 pF X20: 500 kohm NOMINAL | | <25 pF Attenuator: X1 or X20 NOMIONAL, X20 increases to X40 below 50 Hz Low Pass Filter: 100 kHz NOMINAL 3 dB point Channel B Characteristics Range: 50 to 225 MHz Sensitivity: 10 mVrms 50 to 200 MHz, 15 mVrms 200 to 225 MHz Dynamic Range: 10 mV to 1 Vrms Coupling: AC Impedance: 50 ohm NOMINAL Attenuator Level: Manual: variable from X1 to X5 (0 to 14 dB) NOMINAL Auto: AGC mode for improved noise suppression. Damage Level: 350 VDC + 5 Vrms AC Timebase Frequency: 10 MHz Aging Rate: <3 × 10e-7/mo. Temperature: <5 × 10e-6, 0 degrees to 50 degrees C. Ref. to 25 degrees C. Line Voltage: <1 × 10e-7 for ±10% variation. Frequency A and B Range Channel A: 10 Hz - 100 MHz Range Channel B: 50 MHz - 225 MHz LSD Displayed: 10 Hz to 1 nHz LSD ((4 nsec) / (Gate Time)) × FREQ Resolution: ±1 LSD ± ((1.4 × Trigger Error + 1 nsec rms) / (Gate Time)) × Freq Accuracy: ± Resolution ± Time Base Error × Period